I am in blog queue clear-out mode today. Thank you Maxime Barba for flagging the French SC’s December judgment on the application of Rome I’s (in fact the Rome Convention but the provisions have not materially changed) protective regime for employees. At issue is a contract for which parties had chosen Moroccan law, with the Court of Appeal setting aside that choice under A6 Rome Convention, now A8 Rome I, in favour of the French law’s provisions for dismissal, binding upon the employer by virtue of a collective labour agreement.
As Maxime notes, an interesting reference is the SC’s view on what law has to be considered ‘more favourable’. This weighing is a consequence of A6 stipulating
in a contract of employment a choice of law made by the parties shall not have the result of depriving the employee of the protection afforded to him by the mandatory rules of the law which would be applicable under paragraph 2 in the absence of choice.
Clearly setting aside only occurs when the default law (the one that applies in the absence of choice) is more favourable to the employee. How though does one assess that more protective character? Piecemeal, checking every part of the employment relationship? Or more ‘global’, which would mean the exercise might let the employee down on some of the consequences. And once the comparison made, how much of the offending law does one set aside? The SC first of all notes that
 D’abord, la détermination du caractère plus favorable d’une loi doit résulter d’une appréciation globale des dispositions de cette loi ayant le même objet ou se rapportant à la même cause.
The judge’s exercise must limit itself to those parts of labour law which are at issue in the dispute: not an overall comparison, in other words. However as I understand the judgment, the employer had argued that once the comparison made (here: French law including a longer list of dismissal without cause than Moroccan law), the judge must only give sectional priority to the default law: here: the judge, it is argued, must treat the end of the relationship as one without cause, but must then resurrect Moroccan law’s consequences to such dismissal without cause. The SC on the other hand puts a fork in the road: once the road to French ‘dismissal without cause’ taken, French consequences for same apply. (The SC does in the end annul on the basis of a wrong calculation of the severance package, under French law).
EU Private International Law, 3rd ed. 2021, Heading 3.2.5.